The proposed research is a continuation of investigations currently in progress on human zinc nutrition. Specific projects include: the determination of normal ranges for biochemical indices of zinc and copper nutrition throughout pregnancy. Evaluation of the zinc nutrition status of lactating women and correlation with the zinc content of human milk and the zinc status of breast-fed infants. Determining the zinc content of milk from mothers who deliver prematurely. Investigation of factors affecting plasma zinc and copper concentrations in low birth weight infants. Determination of the effect of dietary zinc supplementation in infants and pre-school children with low height percentiles and biochemical evidence of zinc deficiency. Long-term studies of the clinical and biochemical effects of zinc therapy in acrodermatitis enteropathica, and investigations of the basic molecular defect. Investigation of zinc nutrition and metabolism in diabetes mellitus, extra-hepatic biliary atresia, phenylketonuria, pediatric dialysis patients, and failure to thrive.